Process for treating zinkiferous substances.



G. MOJANA.

PROCESS POR TRL'ATING ZINKIFEROUS SUBSTANGES. APPLICATION FILED DB0. 14, 190e.

96L5M Patented June 14, 1910.

L' Y d@ GUIDO MGJANA, OF MILLAN, TALY.' y j PROCESS FOR TREATING ZNKXFEROUS SUBSTANCES.

Eatented June ad, Blfltl Serial No. 347,846.

specification of Letters Yatent.

Militrs.

Application filed December 14, 1906.

mass. For this reason the apparatus for working the process has been so designed as to compel the gases given ott which has been almost completely treated to pass through another mass only slightly treated. Chlorin is thus all absorbed and the gases are set free in the atmosphere..

According to circumstances it is well to inject together with the ehlorin (but only at intervals) a jet of steam.

The reaction between gaseous chlorin and the zinc ores is likely to take place in consequence ot1 the presence of steam, developing either from the humidity, natural or artificial, of the ore under treatment, or from the-humidity the chlorin carries.

The quantity of water required for the reaction is small in comparison 'tt'ith the amount, which would correspond with the quantityof chlorin, as reckoned on the base ot the chemicalequations, this depending upon the circumstance that water is being produced iii the same quant-ity as required by the reaction which is going on.V

The reaction may be considered as consisting ot two phases, respectively by the equations:

(i) engo+2oi2+c=oo2+lnot (e) lnoieznozaznoienzo.

As the chlorid of Zinc thus formed is a strongly hygroscopic substance which absorbs water even at temperature of about ZOGo C., it may happen that, while the chloiination is going on and the amount of chlorid of zinc is increasing, the steam, necessary tor the completion ot the reaction may not be present in the parts ot. the apparatus situated at. a distance from the point of entrance ot chlorin. In this case the introducsteam may prove ad To all whom it may concern:

Be it known that l, GUIDO Momma, civil engineer, subject of the King of taly, residing` at Milan, Italy, have invented new and useful Improvements in Processes for Treating Zinkiterous Substances, of: which the following is a speeication.

` My present invention relates to a process for treating calainin sinithsonite,blende, concentrates and tailings, zinc ashes, namely the residues of the tino plating industry and all other industries Where Zinc is treated, with the object of forming a soluble compound x with the zinc c ntained in such materials; such compound is then extracted from the l remainder of the mass by lixiviation, depurated and eventually electrolyzed in order to obtain metallic zinc.

lt is well known that when calamin, tor l instance, is treated with chlorin in various conditions of temperature and pressure only l a part of the zinc it contains is transformed into chlorid. The same happens with all the ores and materials containing zinc not in the state of suliid. lt the zinc is contained in. the torni of sulfid, as in the blonde, by operqating under certain conditions upon the l, molten mass, the chlorin is rapidly absorbed, sulfur is set free and a chlorid ot zinc is formed, The Ashcroft and Swinburn process is based upon this reaction and cannot be applied to other ores than blends nor to roasted blonde, nor to ashes.

have discovered that by acting in the presence of porous carbon and under certain determined conditions the. zinc contained in the calamin can also be almost totally transformed into a soluble compound (chlorid) and the. same result is obtained with the other zinlriterous substances. The process based upon said discovery may thus also be applied to calcined and uncalcined calamin, blonde smithsonite, zinc ashes, concentrates and tailings. For this purpose lin-ay use charcoal, or colte obtained from the distillation of coal, peat, lignite, and woot, and

tion ot a special jet of vaiitageous.

Other elements influenced are, the temperature, the quantity of carbon and its intimate mixture withdthe ore.

by which the reaction is which is broken intol small particles. lt By the use of the coinniinuted carbon the must be intimately mixed with the zinlriferreactions, by which the clilorid o t. zinc is ons substances and preferably wetted a little formed from the charge, are obtained at a temperature, the reactions taking place at about 100o C., though the best results are obtained at about 200 C.

In the annexed l orawing l have illustrated two diverent forms oif construction of the before mixing the temperature must genercomparatively low ally be above T centigrade; chlorin is at first absorbed in considerable cniantity the absorption then grows less rapid and becomes very slow.I During the operation carbonio acid, oxid of carbon and naturally the chlorin not absorbed are given ed from, the ont my process.

besides the presence of steam, l

anparatusrelich may be used tor carrying` 'from the mass represented ics l retort l from bottom to cock r2 in the pipe u2 top.l When the retort v1 Figure l is a vertical section of a continuous action apparatus. Fig. 2 is a plan view of a modified form, Fig. 3 is an elevation, Fig. 4 a section on line A-B of Fig. 3, and Fig. 5 a section on line p-g of Figs. 3 and 4, of an alternating action apparatus.

The continuous apparatus shown in Fig.

\ l consists of a cylinder S made in one piece or formed of special bricks and mortar that resist the action of chlorin, the cylinder bcing as thin as possible. rlhe pipe 1f in the lower part serves for introducing chlorin. The heating ofthe cylindrical retort is at` tained b y circulating around and inside same the products of combustion of a com` mon furnace properly diluted with air. The hot gases `enter the earthenware pipe L, with thin walls located inside the retort S, and rise through it, then' they come down into the annular chamber C along the retort and again rise alon C2, whence they pass into an iron pipe whlch discharges them into the atmosphere. In the bottom of the retort there is a door for the discharge, the

charging being eiected from the top.

The alternating action apparatus (Figs. 2 to 5) consists of two retorts l, 2 (Fig. 3), arranged in series. These retorts are each surrounded by two annular chambers C', C2

communicating with each other at their lower portion and forming two jackets around the retort. A pipe M connects with the upper part of the annular chamber C and an outlet pipe lea ds from the upper part of the chamber C2. The retorts are heated by the combustion gas from the furnace which enters through the inlet pipe M and passesvdownward through the annular chamber C" and then upward through the chamber C2 to the outlet pipe. vChlorin is introduced so that after it has gone through the top it passes into retort 2 through pipe u2 also from bottom to is saturated with chlorin this is sent direct into retort 2 and the former is then discharged from the bottom by removing the lower cover E (kept against the bottom by a screw). When the retort 1 is recharged chlorin from retort 2 is sent through it until retort 2 is saturated and so on. These operation are effected by using in addition to pipes u and u2 cocks r r2 and R this latter being a three way cock. The pipe a which supplies the chlorin can be connected by the cock R with the pipe b leading to retort l, or with the pipe c leading to retort 2. Vhen the pipe a is connected with pipe b, the chlorin will enter the retort l, and as the retort 1 is then closed at the top, the chlorin, not absorbed with the other gases into the pipe u2. The being open, the chlorin will pass through pipe c into the retort 2 where it will be absorbed. At this time the retort 2 is open at the top so that the gases in retort l, will pass' will be discharged into the atmosphere. During this period the cock 1^ remains closed. When the charge in retort l is saturated, the retort is discharged and is then recharged after the cock R hasbee-n turned so as to cause the pipe a to communicate with the pipe c, and the cock r? has been closed and the cock r opened. Then retort- 2 is closed at the top, retort l being left open at the top after the recharging. This is continued unt-il retort 2 is saturated and then the operation is repeated.

In the continuous apparatus a partial discharge is effected at regular intervals of time and it is then at once refilled from the top until the retort is full.

The two apparatuses described show one of the ways of carrying out my process, but they can be modified in many ways: the retorts for instance may not be of circular section, the inside earthenware pipe L in the first apparatus may be dispensed with or changed as also the circulation of the gases and so on. vWhere convenient the draft of the heating gas may be 'increased by a suc- `ion at the discharge of the heating chain` er. circulating around the retort, in an annular chamber or ljacket, steam at a suitable temperature and pressure or by introducing The heating may also be obtained by steam inside the retort together with the chlorin. An important simplification can be obtained by heating the retort electrically, hat is to say by passing a current of suitable voltage through an'iron coil around the retort or through a mass of granular coke around the retort, or by passing the current through the mass of coke and zinkiferous substance contained in the retort and upon which the chlorin must act. The mass which has been thus treated is first sieved for the purpcse of separating the charcoal from theremainder. This is taken into lixiviation tanks and treated with the washing of said charcoal. The mixture obtained by liXiviation is made hot by the introduction of a jet of steam. It is then passed through a filter press. The solid part which remains in the filter press may eventually be treated in any suitable manner to obtain silver or lead, but this forms no part of the present invention. The liquid containing the chlorids of Zn, Pb, Fe and Mn. are cooled at 0o centigrade and filtered, thus separating Cl2 Pb,; the liquid is then successively treated with oxidants (such` as chlorin, calcium hypochlorite and with subwater 1 stances containing OXid. of zinc (calamin,

roasted blende, calcined calamin or others) and it is then ltered. I thus get a solution of C12Zn which may at once be subjected to electrolysis. Or the said solution may be dried, and in such case the chlorid of zinc thus 'obtained may be placed on the market or it may be melted and in that condition subjected to electrolysis. When treatin the solution or the molten salt by electrolysis the metallic zinc will gather on the cathode and the chlorin on the anode. This chlorin is sent into the chlorinating tub after it has been dehydrated if necessary, and is then heated by passing through an earthen- `Ware coil arranged Within the furnace.

ClzZn may also be separated from the mass discharged from the charcoal, by sublimation in an earthenware retort above the boiling point of ClzZn, concentrating the vapors in a suitable tank, de urating the ClZZn sublimated and electro yzing when necessary. The process, When electrolysis is used, constitutes a closed cycle. In order to make up for the inevitable losses it will be necessary to furnish the cycle with a certain quantity of chlorin from one orthe apparatuses in use for the electrolytic production of soda.

Having nowv fully described my said invention and ho'w the same is to be performed, what I claim is:

1. In a process for the iferous substances, subjecting the said substances to the action ot chlorin in the presence of porous carbonaceous matter and moisture.

2. In a process for the treatment of zinkiferous substances, at a comparatively low treatment of zink-- temperature, subjecting the same to the action of chlorin in the presence of porous carbon and steam.

3. In a process for the treatment of zinkiferous' substances, at a comparatively low temperature, subjecting the same to the action of chlorin in the presence of porous v carbon and steam, removing the carbon from the mass thus obtained, and lixiviating, il-

tering, and treating the liquid residuum with oxidizing a ents and oXid oflzinc.

41. A. process or the treatmentl of zinkiferous substances, at al comparatively low temperature, consisting in subjecting the same to the action of chlorin in the presence of porous carbon and steam, removing the carbon from the mass thus obtained, lixiviating, filtering, and treating the liquid residuum with oxidiz'in agents and substances containingoxi of zinc, to obtain zinc chlorid, and electrolyzing the zinc chlor'id to obtain metallic Zinc.

In testimony whereof I havesigned my name to this specication in the presence of tv vo subscribing Witnesses.

GUIDO MOJANA.

Witnesses :v

B. CARLo SALvoLi, M. SIERSDORFER. 

